Efficient computation of forces on dislocation segments in anisotropic elasticity

We compare several alternative approaches for computing the stress field of a straight dislocation segment and its forces on other segments in an anisotropic linear elastic medium. The Willis-Steeds-Lothe expression can be implemented faster than Brown's formula and the matrix formalism is only slightly faster than the integral formalism. Expressions for self-stress and self-force are also explicitly derived. As an example, the critical stress to activate a Frank-Read source is computed as a function of its length in both isotropic and anisotropic materials.